2014, 373−386 Physicochemical Problems of Mineral Processing

Abstract: Ionic liquids are widely used in supported ionic liquid membranes technology, especially in gas separation and purification processes. This work characterizes the ability of ionic liquids to wet commercially available porous supports used for such purposes. Characterization of supports and membrane phases was carried out in order to determine factors influencing wetting process. Experimental method based on capillary rise is widely used for porous media characterization (i.e. pore radius, contact angle). Measurements of penetration distance or liquid mass are two main experimental methods, in which the Washburn equation is a basic instrument to analyze the obtained results. However, polymeric porous supports do not meet Washburn assumptions and the method is loaded with human errors, so the sessile drop method was used. The rate of wetting influences swelling effects and therefore changes in permeation path during gas separation processes are observed. Influence of ionic liquids structure on wetting and swelling of porous supports was investigated. The families of 1-alkyl-3-methylimidazolium (C n mim), ammonium (N nnnn ), 1-alkyl-1-methylpyrrolidinium (C n Pyrr) and 1-alkylpyridinium (C n Py) compounds with variable alkyl chain lengths in cation structures and changeable anions were taken into account in wetting and swelling experiments

Wetting of supports by ionic liquids used in gas separation processes

Abstract. Ionic liquids were found to be selective solvents for separation of gases. They are widely used in supported ionic liquid membranes (SILMs) technology, especially in gas separation and purification processes. This work has characterized commercially available porous membranes employed in such purposes. Characterization of supports and membrane phases was carried out in order to determine factors influencing membrane stability. Scanning electron microscopy (SEM) was used to determine morphology of membrane surface

Wetting processes in supported ionic liquid membranes technology

Ionic liquids are widely used in supported ionic liquid membranes technology, especially in gas separation and purification processes. This work characterizes the ability of ionic liquids to wet commercially available porous supports used for such purposes. Characterization of supports and membrane phases was carried out in order to determine factors influencing wetting process. Experimental method based on capillary rise is widely used for porous media characterization (i.e. pore radius, contact angle). Measurements of penetration distance or liquid mass are two main experimental methods, in which the Washburn equation is a basic instrument to analyze the obtained results. However, polymeric porous supports do not meet Washburn assumptions and the method is loaded with human errors, so the sessile drop method was used. The rate of wetting influences swelling effects and therefore changes in permeation path during gas separation processes are observed. Influence of ionic liquids structure on wetting and swelling of porous supports was investigated. The families of 1-alkyl-3-methylimidazolium (Cnmim), ammonium (Nnnnn), 1-alkyl-1-methylpyrrolidinium (CnPyrr) and 1-alkylpyridinium (CnPy) compounds with variable alkyl chain lengths in cation structures and changeable anions were taken into account in wetting and swelling experiments

Preparation and physicochemical characterisation of ceramic supports for suported liquid membranes

Supported liquids membranes are very promising products. They have been intensively inves-tigated in last two decades and widely used in many technologies especially in gas separation and purifi-cation processes. A key aspect in obtaining satisfying effectiveness and long membrane lifetime is a proper choice of ionic liquid and polymeric or ceramic support. Properties of both affect the processes of obtaining useful supported ionic liquid membranes. In comparison to polymeric membranes, ceramic ones are slightly thicker, however they are thermally and mechanically more stable. Our research was aimed at sintering fine glass particles of 500 to 45 μm in size in order to prepare porous membranes which can be used as supports for liquid membranes. Dextrin and borax were used as pore-making agents. The membranes, as disks 35 mm in diameter and 3 mm of thickness, were prepared. The porosity was determined using absorption method. It was found, that the porosity could be controlled by changing the applied pressure from 1 to 5 MPa, particle size distribution, sintering temperature, type and amount of pore-enhancing agents